Device for cutting braided chemical fibers

ABSTRACT

The device is provided with a cylindrical cutter shaft with a sharp helical cutting edge. Rectangular slots with a constant angular pitch are provided on the cutter shaft along the generatrices of the cylinder. Owing to the provision of slots, part of the fibers in the braid remain uncut. This makes it possible to produce a comparatively strong staple sliver wherein upon subsequent drawing differential displacement of the fibers with respect to one another is possible.

O Umted States Patent 1191 3,776,084 Slyvakov Dec. 4, 1973 [5 DEVICE FOR CU'I'IING BRAIDED 2,221,716 11/1940 Morton 83/672 x CHEMICAL FIBERS FOREIGN PATENTS OR APPLICATIONS lnvemofl Vladimir Egomviclt Slyvakov, 854,829 11/1952 Germany 19/.6

Bolotmkovskaya uhtsa, 46, korpus Moscow USSR Primary ExaminerJ. M. Meister [22] Filed: Apr. 24, 1972 Attorney-John C. Holman et al.

[52] U.S. CI. 83/342, 19/.6, 83/346, 83/678, 83/913 [51] Int. Cl. D01g 1/10 [58] Field of Search 19/.6, .62; 83/332, 83/342, 346, 347, 672, 678, 913

[56] References Cited UNITED STATES PATENTS 3,570,337 3/1971 Morgan 83/678 X 3,152,501 10/1964 Nassar 83/678 X Appl. No.: 246,544

[57] ABSTRACT The device is provided with a cylindrical cutter shaft with a sharp helical cutting edge. Rectangular slots with a constant angular pitch are provided on the cutter shaft along the generatrices of the cylinder. Owing to the provision of slots, part of the fibers in the braid remain uncut. This makes it possible to produce a comparatively strong staple sliver wherein upon subsequent drawing differential displacement of the fibers with respect to one another is possible.

2 Claims,'2 Drawing Figures .1 DEVICE FOR CUTTING'BRAIDED CHEMICAL FIBERS BACKGROUND OF THE INVENTION The present invention relates to theprocessing of chemical fibers, and more particularly to the cutting of braided chemical fibersand the production of stapled sliver.

This device can be used with the greatest success in all branches of the textile industry in theproduction of yarn from braided chemical fibers both .in the .pure state and mixed with natural fibers.

There are known devices'for cutting braided chemical fibers comprising a smooth cylindrical supporting shaft mounted in stationary'supports, and a cylindrical cutter shaft having a helical cutting edge parallel to and above it.

In these devices the cutter shaft is so spring-loaded that it is pressed against the supporting shaft with a certain force.

The cutting edge of the cutter shafthas in section the shape of a triangle with a cut off apex. The cutting edge is blunted and has a width of 0.2-0.35 mm.

The principal shortcoming of this device for cutting braided chemical fibers is the fact that upon the interaction of the cutter shaft and the smooth supporting shaft between which the braid passes, the fibers are not cut, but crushed. The ends of the fibers become welded together, and as a result the lengths of fibers poorly lend themselves to relative displacement in the staple upon the following drawing of the stapled sliver.

The stapled sliver produced in this way from crushed braided chemical fibers is not uniform in thickness. To eliminate this technological defect a number of addi tional technological operations are required, such as comb carding, and several passes of the sliver machines (two to four).

SUMMARY OF THE INVENTION An object of the present invention is to provide a device that would make it possible to produce a stapled sliver having adequate strength, and in which differential displacement of the fibers in the staple would occur upon further processing.

Another object of the present invention is to improve the quality of stapled sliver and reduce the number of technological passes required up to the production of the yarn, and also to increase the output of the stapling machine, reduce the number of operations required in the yarn production process and increase the effectiveness of utilizing chemical fibers.

The device for cutting braided chemical fibers according to the present invention comprises a smooth cylindrical shaft mounted in stationary supports, and a cylindrical cutter shaft having a helical cutting edge parallel to and above it.

Rectangular slots with a constant angular pitch are provided on the cutting edge of the cutter shaft along the generatrices of the cylinder.

The cutter shaft is so arranged relative to the smooth supporting shaft that there are no gaps between them. The cutter shaft is pressed against the supporting shaft by means of a definite load, for example, a spring load.

Such a design of the device makes it possible to perform difierentiated' cutting of braided chemical fibers and to obtain a stronger stapled sliver, and also ensures displacement of the'fiberswith'respectto one another upon the'following drawing or the stapled sliver.

It is expedient for the cuttershaftto' have a sharp cutting edge. In this case 'the' 'fiber will be cut, and not crushed, which ensures the absence of welded spots and facilitates the further processing of the stapled sliver.

BRIEF DESCRIPTION OF THE'DRAWINGS The nature of the present invention will become more fully apparent from a consideration of the following description of an exemplary embodiment thereof, taken in conjunction with'the accompanying drawings, in which:

"FIG. 1 is a shematic general view of the device for cutting braided chemical fibers according to the invention;

FIG. 2 is a section of the cutter shaft along the cutting edge.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The device for cutting braided chemical fibers comprises smooth cylindrical supporting shaft 1 mounted in stationary supports 2. Cutter shaft 3 provided with helical cutting edge 4 is arranged parallel to and above shaft 1. Cutting edges-4 have the shape of a triangle in cross section. Rectangular slots 5 areprovided inthe cutter shaft along the generatrices of the cylinder.

The depth h of longitudinal slots 5 should ensure that the fiber enters them along the entire thickness of the cloth, while the width b and the pitch t of slots 5 should ensure the non-cutting of the given number of fibers both between separate staples and as a whole along the entire width of the cloth so as to ensure, by means of the uncut fibers, differential displacement of the fibers in the staples having a given length of cutting with respect to one another upon drawing of the cloth. The length l of the fiber in cutting is determined by the diameter of cutter shaft 3 and the number of starts of helical cutting edge 4.

Cutter shaft 3 is pressed to supporting shaft 1, for example, by means of springs (not shown in the drawings).

The device functions as follows.

Supporting shaft 1 is the driving shaft of the device. Upon its rotation the braid being fed into the machine is gripped and passes between supporting shaft 1 and cutter shaft 3. Shaft 3, owing to the forces of friction, also begins to rotate. The braid of chemical fibers between shafts l and 3 acquires forward motion.

Upon passing between supporting shaft 1 and cutter shaft 3, a preset number of fibers is cut into parts having a definite length. The length l of each part depends on the diameter of cutter shaft 3 and the numberof starts of helical cutting edge 4. The depth h and the width b of slot 5 on cutting edge 4 is selected depending on the thickness of the braid and on what part'of the fibers has to be cut.

Upon subsequent drawing, owing to the partial cutting of the braid fibers, differential displacement of the fibers with respect to one another in the staples is ensured. This results in the production of a stapled sliver that is uniform in thickness.

The design of the device for cutting braided chemical fibers according to the present invention makes it possible to produce a stapled sliver with a uniform thickdrical cutter shaft means being provided with cutting means for cutting said fibers, which cutting means defines a cutting edge helically disposed on said cylindrical cutter shaft means, said cutting 5 edge having rectangular slots disposed thereon and thus along the generatrices of said cylindrical cutter shaft means. 2. A device as claimed in claim 1, wherein said cutting edge is sharpened for cutting'said fibers so that at any point along its length said cutting edge has a substantially triangular cross section with said sharpened edge forming the apex thereof.

t 0 t I! 

1. A device for cutting braided chemical fibers including: a smooth cylindrical supporting shaft means; a stationery support means for mounting thereon said smooth cylindrical supporting shaft means; a cylindrical cutter shaft means mounted parallel to and above said supporting shaft means, said cylindrical cutter shaft means being provided with cutting means for cutting said fibers, which cutting means defines a cutting edge helically disposed on said cylindrical cutter shaft means, said cutting edge having rectangular slots disposed thereon and thus along the generatrices of said cylindrical cutter shaft means.
 2. A device as claimed in claim 1, wherein said cutting edge is sharpened for cutting said fibers so that at any point along its length said cutting edge has a substantially triangular cross section with said sharpened edge forming the apex thereof. 